<!DOCTYPE html>
<html>
<head>
<meta charset="ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
	<script>
		function clickMe(checkbox){
			if(checkbox.checked)
			
				alert("checked");
			else
				alert("Unchecked")
			
		}
	</script>
	<input type="checkbox" onClick="clickMe(this)">
</body>
</html>